The present invention relates to a transponder for a tire condition monitoring apparatus that wirelessly transmits data representing the condition of a tire in response to radio waves having a field intensity equal to or greater than a predetermined level.
For example, Japanese Laid-Open Patent Publication No. 5-169931 discloses a tire having a transponder. The transponder has a coil antenna for wirelessly transmitting the condition of the tire attached to a vehicle. When an interrogating electromagnetic field is generated outside the transponder, electricity is induced by the coil antenna. Based on the induced electricity, the transponder wirelessly transmits data representing, for example, identification of the tire.
However, since the transponder of the publication is accommodated in a tire, the transponder is changed when the tire is replaced by a new tire.
Further, since the new tire must have the same type of transponder, the choices of tire are limited. Also, to process the removed tire, the accommodated transponder must be removed, which creates an additional work. That is, the transponder cannot be separated from the tire main body. This adds to inconvenience when replacing and scrapping the tire.